Error with zksync rpc-url: {Failed to serialize transaction: toAddressIsNull}

[Tarreef]

Just coming from Alchemy and...

I created a new app called test_Zksync with zksync. with the intension to get a new rpc-url for deployments... i ran it through the .env file. then used bash to deploy it...

forge script script/DeploySol.s.sol --rpc-url https://zksync-sepolia.g.alchemy.com/v2/AeH5nngTalEuno4GrfZ7r0GoAZVt-Px6 --account SolKey1 --broadcast --legacy

after the return key i kept getting this error...

[⠊] Compiling...
No files changed, compilation skipped
Enter keystore password:
Warning: EIP-3855 is not supported in one or more of the RPCs used.
Unsupported Chain IDs: 300.
Contracts deployed with a Solidity version equal or higher than 0.8.20 might not work properly.
For more information, please see https://eips.ethereum.org/EIPS/eip-3855
Script ran successfully.

== Return ==
0: contract SimpleStorage 0x6d9327cc7Fc2d35383CC718db3860fcB9BfD0f71

## Setting up 1 EVM.

==========================

Chain 300

Estimated gas price: 0.025 gwei

Estimated total gas used for script: 763794

Estimated amount required: 0.00001909485 ETH

==========================

Transactions saved to: /home/tarreef/foundry-f25/foundry-simple-storage-f25/broadcast/DeploySol.s.sol/300/run-latest.json

Sensitive values saved to: /home/tarreef/foundry-f25/foundry-simple-storage-f25/cache/DeploySol.s.sol/300/run-latest.json

Error: Failed to send transaction

Context:
- server returned an error response: error code 3: Failed to serialize transaction: toAddressIsNull

And i'm certain i have zksync testnet funds in the SolKey1 account.

So what could be the issue spawning up this error
- server returned an error response: error code 3: Failed to serialize transaction: toAddressIsNull

[EngrPips]

Hello @Tarreef, Foundry script doesn't work well with zksync you should try to deploy with forge create command or maybe use a bash script.

Just more context when you deploy on chain like Ethereum your deployment bytecode is sent to the zero address and that is how the EVM knows that your transaction is meant to deploy a contract, This exactly how foundry script work for deploying contract, But for zksync when you want to deploy a contract you send your contract bytecode to a deployer contract on the zksync chain which will then deploy your contract.

So when you use Foundry to deploy a contract on zksync chain it tries to send the deployment bytecode to address(0) which is the wrong address for contract deployment on zksync hence the error - server returned an error response: error code 3: Failed to serialize transaction: toAddressIsNull

Here https://docs.zksync.io/zksync-protocol/differences/contract-deployment to read more about this details

[Tarreef]

Ok, i tried the forge create...

this --> forge create src/DeploySol.sol:SimpleStorage --rpc-url https://zksync-sepolia.g.alchemy.com/v2/AeH5nngTalEuno4GrfZ7r0GoAZVt-Px6 --account SolKey1 --legacy --broadcast

i ran it.. and still got Error: server returned an error response: error code 3: Failed to serialize transaction: toAddressIsNull

[KMean]

Ok, i tried the forge create...

this --> forge create src/DeploySol.sol:SimpleStorage --rpc-url https://zksync-sepolia.g.alchemy.com/v2/AeH5nngTalEuno4GrfZ7r0GoAZVt-Px6 --account SolKey1 --legacy --broadcast

i ran it.. and still got Error: server returned an error response: error code 3: Failed to serialize transaction: toAddressIsNull

try to add --zksync flag at the end of your command

forge create src/DeploySol.sol:SimpleStorage --rpc-url https://zksync-sepolia.g.alchemy.com/v2/AeH5nngTalEuno4GrfZ7r0GoAZVt-Px6 --account SolKey1 --legacy --broadcast --zksync

[Tarreef]

yes it deploys successfully. it works!!